α-Neoendorphin (1-8) is a 8-amino acid peptide derived from the N-terminal of α-Neoendorphin. α-Neoendorphin is an endogenous opioid peptide and is a part for the neoendorphins which are a group of endogenous opioid peptides derived from the proteolytic cleavage of prodynorphin isolated from procine hypothalmus and pituitary.

Somatostatin, also known as growth hormone-inhibiting hormone, is a naturally-occurring peptide hormone of 14 or 28 amino acid residues that regulates the endocrine system. It is secreted by the D cells of the islets to inhibit the release of insulin and glucagon, and is also generated in the hypothalamus, where it inhibits the release of growth hormone and thyroid-stimulating hormones from the anterior pituitary.Somatostatin is a tetradecapeptide which can suppress the growth hormone (GH) secretion and control the pituitary hormone secretion in human CNS.

Substance P (5-11) 是 Substance P (Substance P ) 的 C 端七肽 ，是一种神经肽，可以与 NK-1 速激肽受体结合。